Cards that store data are becoming more popular, especially chip cards, or smart cards, that include an imbedded memory chip connected to pads on a surface of the card near its front end. A card reader assembly includes a housing with a slot that receives the card and a card reader that comprises contacts that engage the card pads. It is desirable to place some of such card reader assemblies in unattended public places, such as in pay telephones and product and money vending machines, where members of the public insert their own cards through the slots. However, there is a possibility of damage to the card reader assemblies by casual vandals. Such vandals may insert thin objects such as knives or keys, to see if they are able to make the assembly erroneously recognize a smart card and dispense goods, authorize a telephone call, etc. Also, polluters may insert objects such as gum wrappers into the card slot. It would be desirable if the assemblies could block the deep insertion of foreign objects, so they are prevented from reaching the card reader and damaging its pad-engaging contacts. Also, it would be desirable if the assembly were constructed to avoid obstruction of the card path by objects left therein by vandals or inserted therein by polluters.